Improvement in piano-actions



R. KRETER. Piano Actions.

No. 145,879, Patented Dec. 23,1873.

l mu" I I v1 r I c UNITED STATES PATENT QFFIGE.

RUDOLPH KRETER, or NEW YORK, N. Y.

IMPROVEMENT IN PIANO-ACTIONS.

Specification forming part of Letters Patent No. 145,879, dated December 23, 1873 application filed November 22, 1873.

To all whom it may concern:

Be it known that I, RUDOLPH KRETER, of the city, county, and State of New York, have invented certain Improvements in Piano- Forte Actions, of which the following is a specification This invention mainly relates to what is known as the Erard action for piano-fortes, and consists partly in an improved construction. of the repeating-lever and jack; also, in providing the repeating-lever with a steadyingtongue or repeating-cheek, and in a post or wire holding the spring which controls the repeating-lever, and a regulating-button for adjusting the repeating-lever irrespective of the jack; also,in the novel construction of the letting-off prop. By these improvements, and other ehan ges of construction pertaining thereto, a more perfect and free action is obtained, and much of the action may be made by machinery that heretofore has been made by hand.

Figure 1 represents an elevation of my improved action when at rest; Fig. 2, a plan of the same, with the hammer removed and hammer-butt broken away; Fig. 3, a perspective view, in part; Fig. 4, an elevation of the action after the hammer has struck, and with the jack SUPPOltll'lg the same; Fig. 5, a similar view prior to the falling of the jack under the hammer, and with the hammer under the control of the repeatingcheck.

Similar letters of reference indicate corresponding parts in all the figures.

A is one of the keys of a piano'fortc, and B the bottom or support for the lower lever ot' the action pertaining to said key. G is the hammerrail; D, the let-oft rail; E, the let-off prop, and F the action-rail. G is the hammer; H, the regular hammer-check; I, the repeatinglever; K, the bottom lever, and J the jack; K, the repeating-check.

The jack J, instead of being arranged to project through a slot in the repeatinglever I, to take its bearing under the shoulder b of the hammer, as is the usual construction, is cut away on its one side, as at c, and the repeating-lever made with a similar cut, at, whereby not only is there less tendency of the jack to rub or bind,but I am enabled to give the jack even a broader bearing-surface in its support of the hammer than the leathering of the shoulder 1), thereby doing away with that liability, which heretofore has been, of the jack wearing a hole or depression in the leatherin g of the shoulder b, to the interference of the regular and proper working of the action, and to the sticking of the jack in the lcathering of the shoulder. The knuckle or butt S of the hammer is constructed with a recess, 0, in its under side, immediately in front of the shoulder b, and the leathering of the shoulder extended so as to line the same. The object of this recess is to provide for the reception of a curved tongue or repeating-check, K, on the lever I, which, as the hammer leaves the strings f, serves, by rubbing or bearing against the front or one side of the leathered recess 0, to temporarily hold in check the hammer in advance of the jack J falling under the shoulder b, and of the hammer coming down on the permanent check or rest H, as illustrated in Fig. 5, and whereby a very rapid repeating action may be obtained, and the hammer is restrained from dancing, and the hammer held up till thejack J gets under the shoulder 12. L is a post or wire arranged to project from the bottom lever K, and to pass up through the repeatiuglever I, and bent at its upper end for the attachment of a spiral spring, 9, to control the action of the repeating-lever, subject to an adjusting-button, h, arranged to fit a screw-thread on the post L, and whereby the repeatinglever may be regulated independently of the jack J, or without interfering with the latter, said jack being controlled by a separate spiral spring, 11. This arrangement of independent springs, too, does away with that liability to creak or make a noise of the ordinary single wire spring, which is made to control both the repeating-lever and jack, and is supported in a slot in the post, on which the repeating-lever has its fulcruin. The let-off prop E, against which the "foot of the jack strikes, is connected, intermediately of its length, by screws or otherwise, with the under side of the letoit' rail D, and made adjustable at its outer end by a regulating-screw, k, to determine the distance the hammer has to drop off from the string.

the lovers K I the spring g, and button 71, substantially as herein described.

4. The let-off lever E and its adjusting-screw 7;, in combination with the rail 1) and jack J, essentially as specified.

KUDOLPII KRETE'R.

Witnesses:

MICHAEL RYAN, FRED. HAYNES. 

